Curved Edges on 2 Similar Parts Won't Display in ISO View in Drawing Mode in 2000i2

This happens on the top level assembly drawing only, the sub-assembly
drawing is OK. The part is simply a extruded half-round gasket where
the long axis vertical and is assemblied as part of a circuit card.
When in hidden line view display and oriented to a trimetric view the
half round edges display fine, but in an iso view or close to it they
will not. In wireframe the edges show in any orientation. I've tried
modifying the edge display and member display, but it was of no help.

TIA

 

When in hidden line view display and oriented to a trimetric view the

I don't think I'm getting a good idea of what the part looks like except
that it's a gasket. Any geometry checks? Possible that tightening up the
part's accuracy will have any effect?

 

Check for interference(s) in your top level assembly. Interference(s)
will cause Pro/Engineer to have problems displaying edges in drawing
views.

 

Thanks for the help Guys. Turns out there was an interference along
the vertical edge in the sub-assy which cause the problem with the top
curved edge in the top level.